Abstract

In this paper, the performance of both GaAs and InP-based 0.15um dual-gate HEMTs in a cascode configu­ration is demonstrated by the successful design and realisation of a number of coplanar amplifiers. For a reactively matched single-stage GaAs PHEMT amplifier a gain of 20.9dB is obtained at 23GHz. At millimetre-wave frequencies, this gain can be further improved by using InP-based HEMTs as is shown by the realisation of a single-stage LM HEMT dual-gate amplifier with a stable gain of 16.4 dB and a good in-and output matching at 58.5 Ghz.